(a) Field of the Invention
The present invention relates to a golf club head, especially relates to so-called an iron golf club head or a putter golf club head.
(b) Description of Prior Art
Golf club head generally comprises a face for striking balls, a back, a sole, a top, a heel and a neck for mounting a shaft thereto. Conventional golf club heads such as iron heads or putter heads have had the above-mentioned parts integrally formed of metallic material such as iron by forging. However, such integrally formed heads have been liable to cause a sense of unstability in swinging, and generally had narrower sweet area. What is called sweet area is a certain area on face where golf balls are capable of travelling more straight and a longer distance when they are struck. It is widely recognized that to enlarge a sweet area, the center of gravity of the whole club head should be positioned backward, and/or, the weight distribution of the head should be concentrated on a peripheral portion relative to the face.
On the other hand, it is mainly for the purpose of making a golf ball travel more upwardly and a longer distance to lower the center of gravity of a club head. One of the representative of a means for realizing such weight distribution is disclosed in U.S. Pat. No. 3,847,399, in which a head body is formed hollow, or a back surface of a club head is formed with a cavity.
However, especially for an iron club head, it is difficult to make the same hollow. Further, only a cavity formed in a back surface of a club head made of a single material cannot sufficiently concentrate the weight distribution of a club head upon a peripheral portion, thus setting limits to enlargement of a sweet area.